title: Randomized, prospective comparison of increased preload versus inotropes in the resuscitation of trauma patients: effects on cardiopulmonary function and visceral perfusion.
abstract: OBJECTIVE
  To evaluate the effects of maintaining increased levels of preload on cardiopulmonary function and visceral perfusion during resuscitation.
  
  
  METHODS
  Randomized, prospective study of 39 consecutive trauma patients with a low right ventricular ejection fraction (<40%) admitted to a university Level I trauma center during a 10-month period. Patients were randomized to one of two groups: increased preload (PL), or normal preload with inotropes (INO). The PL group received fluid administration to maintain a target right ventricular end-diastolic volume index (RVEDVI) > or = 120 mL/m2 during resuscitation. The INO group had inotropes added according to a prospectively determined protocol and was maintained at a RVEDVI of 90 to 100 mL/m2. Systemic perfusion was assessed using oxygen transport and acid-base parameters, and pulmonary function was evaluated with PaO2/FiO2 ratio, dynamic compliance, ventilator days, and incidence of adult respiratory distress syndrome. Gut perfusion was assessed by measuring gastric intramucosal pH (pHi). Data are expressed as means +/- SD.
  
  
  RESULTS
  The mean RVEDVI was significantly higher in the PL group (n = 19) than in the INO group (n = 20) during resuscitation (119+/-18 vs. 103+/-22 mL/m2, p = 0.01). There was no difference in oxygen delivery, mixed venous oxygen saturation, lactate, PaO2/FiO2 ratio, dynamic compliance, or ventilator days between the groups. The incidence of adult respiratory distress syndrome was not significantly different (PL 31% vs. INO 50%, p > 0.1). In the patients who had pHi measured sequentially during resuscitation (PL = 13, INO = 17), the final pHi was significantly higher in the PL group (7.31+/-0.1 vs. 7.16+/-0.2, p = 0.03).
  
  
  CONCLUSIONS
  Patients resuscitated at higher levels of preload have significantly better visceral perfusion than those resuscitated at normal preload with addition of inotropes. This higher preload does not adversely affect pulmonary function.
authors.affiliation: Department of General Surgery, The Bowman Gray School of Medicine of Wake Forest University, Winston-Salem, North Carolina 27157, USA.
authors.forename: P R
authors.initials: PR
authors.lastname: Miller
authors.forename: J W
authors.initials: JW
authors.lastname: Meredith
authors.forename: M C
authors.initials: MC
authors.lastname: Chang
mesh_terms: D000328:Adult; D002316:Cardiotonic Agents / Q000627:therapeutic use*; D002423:Cause of Death; D004280:Dobutamine / Q000627:therapeutic use; D004298:Dopamine / Q000627:therapeutic use; D005440:Fluid Therapy / Q000379:methods*; D006801:Humans; D008170:Lung Compliance / Q000187:drug effects; D008875:Middle Aged; D009104:Multiple Trauma / Q000188:drug therapy* / Q000503:physiopathology*; D010101:Oxygen Consumption / Q000187:drug effects; D011446:Prospective Studies; D011669:Pulmonary Wedge Pressure / Q000187:drug effects*; D012151:Resuscitation / Q000379:methods*; D013152:Splanchnic Circulation / Q000187:drug effects*; D013318:Stroke Volume / Q000187:drug effects*; D016896:Treatment Outcome; D014692:Ventilation-Perfusion Ratio / Q000187:drug effects; D014882:Water-Electrolyte Balance / Q000187:drug effects
chemical_list: D002316:Cardiotonic Agents; D004280:Dobutamine; D004298:Dopamine